Note: This is an archival copy of Security Sun Alert 201744 as previously published on http://sunsolve.sun.com.
Latest version of this security advisory is available from http://support.oracle.com
as Sun Alert 1001284.1.

Security Vulnerability With Java Web Start Related to Incorrect Use of System Classes

CategorySecurity

Release PhaseResolved

ProductJava 2 Platform, Standard Edition

Bug Id
6461918

Date of Resolved Release30-APR-2007

Impact

A security vulnerability in Java Web Start may allow an untrusted application to elevate its privileges. For example, an application may grant itself permissions to read and write local files that are accessible to the user running the Java Web Start application.

Sun acknowledges, with thanks, the Fujitsu security team, for bringing this issue to our attention.

Java Web Start in SDK and JRE 1.4.2_13 and earlier for Windows, Solaris and Linux

To determine the version of Java installed on a system, the following command can be used:

% java -fullversion
java full version "1.5.0_02-b09"

Symptoms

There are no reliable symptoms that would show the described issue has been exploited.

Workaround

To workaround this issue, users should avoid using Java Web Start with untrusted applications, and may also wish to temporarily disable the use of Java Web Start.

To disable Java Web Start applications from being automatically launched from a web browser, the following steps can be performed:

For Internet Explorer:

Right click on the "Start" button and select "Explore"

In the "Start Menu" window, select "Tools" => "Folder Options"

From the "Folder Options" window, select the "File Types" tab

From the "Registered File Types" window, scroll down and locate the "JNL - JNLP File"

Select the "JNLP - JNLP File" and click the "Delete" button

For Mozilla:

Select "Preferences" under the browser's "Edit" menu

In the "Preferences" window, select "Helper Applications" located under the "Navigator" category

Under "Files types", scroll down and locate "application/x-java-jnlp-file"

Select "application/x-java-jnlp-file" and click the "Remove" button

Note 1: On Microsoft Windows, applications may also be launched from the desktop icon or Start Menu if a shortcut was previously created for an application. Unknown applications should not be launched through the desktop icon or the Start Menu. Shortcuts can be removed by using the Java Web Start Application Manager through the "Application/Remove Shortcut" menu item.

Note 2: It is also possible to launch applications through the command line in Windows, Solaris, and Linux. Unknown applications should not be launched through the command line. Sites may consider renaming the Java Web Start launcher ("javaws.exe" for Windows and "javaws" for Solaris and Linux) to prevent Java Web Start from launching.

Note: It is recommended that affected versions be removed from your system. For more information, please see the installation notes on the respective java.sun.com download page and the following for the Windows platform: